Inkscape will do what you require. Inkscape is a free, multi-platform program which has a "trace bitmap" feature in the Path menu.
Some details were lost as I did not adjust any of the default parameters. The process took about ten to fifteen seconds to accomplish.
The result will be an SVG (vector) image, but you can export the image to PNG via the file ...
IrfanView is a free image-editing tool with a many batch-operation options, as shown below, and the JPEG save dialog includes the progressive option.
It is a Windows application, but runs well under wine in Linux (and is available in a Snap port), so it might work in wine on MacOS, also.
The only possible disadvantage is the large number of choices, but ...
OpenCV is a Google Sponsored library which includes a series of features for image processing and object identification.
TensorFlow is another Machine Learning stack capable of this, but requires some training.
You can use pdfimages from the Xpdf tools (available from the site of XpdfReader). It will not convert a whole PDF page to an image, rather it will extract embedded images from a PDF.
This is useful if the PDF contains text and images, and you want only the images. Also, it will extract the images in their original format, so no loss of quality is involved (...
This is a clear case for Blender in my opinion. Freeware, super-robust, Linux, Mac and Windows, and exceptionally powerful and flexible - enough so that despite being freeware, it's finding acceptance in the 3D industry in commercial pipelines - because it does what it does quite well.
Hope that helps.
I was going to say Blender in a comment but you've mentioned it already.
Ease of use is most important. I tried blender and was blown away by the interface.
Blender can also be run almost completely with Python, if you are comfortable with Python then you almost never need to use the GUI or touch a mouse, which I also find intimidating.
update: I ...
A few weeks ago I stumbled on your/this question. Having some time on my hands and finding it an interesting technical challenge I decided giving it a try myself.
It resulted in the repository https://github.com/thieupepijn/ComicPanelSplitter
This repository contains, apart from the source code, also a binary for Windows (under release). Hope this program ...
I have spent some hours under this issue and via lots of testing I found that when you put a white border around the aztec code image, then it works quite well and fast :-) I use it in my app: //for the barcode bitmap (string) scanning: implementation 'com.google.zxing:core:3.3.3' //FOR THE CAMERA SCANNING: implementation 'com.journeyapps:zxing-android-...
I found these online services that do offer online GIF compression including a deduplication in frames:
(Does not explicitly advertise this deduplication, but I checked the resulting GIFs.)
(Just to provide an alternative. Their max upload file size is 16MB which was too low for me so ...